Veneering a Large Half-Column
How to veneer fiberglass columns. January 29, 2009
Question
I’m looking for any suggestions on how to veneer an 18" halved column. The columns are pilasters for a home theater. They are 90" tall and are made of fiberglass. The client has provided paperbacked maple veneer.
Forum Responses
(Veneer Forum)
From contributor H:
I would give the customer back his/her maple veneer. This is one peeve I always have with clients. Ask them to take their veneer to a more experienced shop or get real wood columns made or hire a faux painter and have them painted. A last option is to get set up with a vacuum bag and risk doing it yourself. Make sure to charge them enough though.
From contributor H:
What about the caps and bases? You can't veneer them.
From the original questioner:
Real wood columns are out. There is a steel structural element being hidden behind the columns. As far as the caps and bases go, I have already made them. Per the interior decorator they are being painted. So, I was able to make them out of stacked MDF. Even if I supplied the veneer, I would still have some problems wrapping a column this size. Not to mention, what adhesive will work best? I am just fishing for some hints.
From contributor F:
Fiberglass tubes are not your friend and an enemy of wood veneer. Maple is about the most unstable veneer you could employ. Is the column shape round? Have you thought about a fiber tube, as in fiberboard, or a plywood tube? Where has the veneer been stored since it was sliced?
May I assume that you will use 1/2 columns or will seaming be an issue where the veneer ends come together? If a full 18" round the circumference is a little more than 56-1/2". When the tube material is locked in an adhesive discussion can start. At this point friendly adhesive solutions are tough.
From the original questioner:
Unfortunately the fiberglass and maple are locked in due to budget concerns. I did not start this job, but I have been contracted to finish it. These materials would not have been my first choice either. They are 1/2 columns, and there is a piece of 1/4 round where they meet the wall. The veneer sheets are 96" X 36". Seams should not be problem. The room is climate controlled so moisture should be minimal.
From contributor C:
Do you have a vacuum bag that can accommodate this half column? If yes, then I suggest the following:
1. If you don't already have some evacu-net (available from Vacuum Pressing Systems), buy enough to cover the column.
2. Cold press the veneer, using a pva, onto 1/8" bending ply. If you press this in a bag then press it for no more than 30 minutes. You want the glue to be tacky, but not dry. You do not want a rigid glue for this part of the application. You'll need the flexibility of a pva to pull this off. You'll also need at least one or two assistants.
3. Spread epoxy over the fiberglass column, lay the 1/8" veneered bending ply onto the column, wrap with the evacu-net and place it all into the bag. You may want to consider using the West System for this and opt for the slow setting hardener. Turn on the vacuum pump and let it sit over night, or even over the weekend. This will work if you practice with a dry run or two.
Another option is to apply Bondo to the surface of the fiberglass, sand it until it is smooth and free of surface irregularities and apply NBL (No Black Line) to the surface using contact cement. I have never tried this latter approach, but would not hesitate with the former.
From contributor D:
A few years ago I had this same situation with a home theater. We were using birdseye maple veneer over a PVC type sewer pipe. We used polyurethane glue and put it in a vacuum bag. The job was for a high end cabinet that ended up in the Audio Video Interior magazine. It has been well over 5 years since we did that job and have never had a problem with it. We sanded the columns with 60 grit sandpaper on a belt sander and then used the polyurethane glue and the process worked well for us.
From contributor F:
PVC Pipe is an excellent substrate but must be sanded to remove the surface glaze left from the manufacturing process.
From contributor K:
Could one of you guys explain what specifically is the problem with gluing veneer to fiberglass? Is it not smooth enough, too smooth, or is there a chemical problems? I'd like to be able to articulate my response should I be faced with the situation.
From contributor D:
I would think the polyurethane glue would work for the fiberglass as well if it was sanded to remove the smoothness of the finish. The polyurethane glue seems to be able to adhere dissimilar surfaces together for a good bond.
From contributor D:
You do need to vacuum bond it as it does need pressure for the entire drying time.
From contributor R:
What if you make a plywood radius veneered sock in the shop and apply it in the field. Instead of veneering maple to a fiber on site, make a 1/8” round cover, vacuum it in the shop and slap it on on-site.
